Support generating HIE files

Adds a `-fenable-ide-info` flag which instructs GHC to generate `.hie`
files (see the wiki page:
https://ghc.haskell.org/trac/ghc/wiki/HIEFiles).

This is a rebased version of Zubin Duggal's (@wz1000) GHC changes for
his GSOC project, as posted here:
https://gist.github.com/wz1000/5ed4ddd0d3e96d6bc75e095cef95363d.

Test Plan: ./validate

Reviewers: bgamari, gershomb, nomeata, alanz, sjakobi

Reviewed By: alanz, sjakobi

Subscribers: alanz, hvr, sjakobi, rwbarton, wz1000, carter

Differential Revision: https://phabricator.haskell.org/D5239

6 files changed, 134 insertions, 34 deletions

diff --git a/compiler/main/DriverPipeline.hs b/compiler/main/DriverPipeline.hs
index 295d36284f..f1a5cb46e0 100644
--- a/compiler/main/DriverPipeline.hs
+++ b/compiler/main/DriverPipeline.hs
@@ -75,6 +75,8 @@ import Data.Maybe
 import Data.Version
 import Data.Either      ( partitionEithers )
 
+import Data.Time        ( UTCTime )
+
 -- ---------------------------------------------------------------------------
 -- Pre-process
 
@@ -1016,6 +1018,7 @@ runPhase (RealPhase (Hsc src_flavour)) input_fn dflags0
 
         let o_file = ml_obj_file location -- The real object file
             hi_file = ml_hi_file location
+            hie_file = ml_hie_file location
             dest_file | writeInterfaceOnlyMode dflags
                             = hi_file
                       | otherwise
@@ -1023,7 +1026,7 @@ runPhase (RealPhase (Hsc src_flavour)) input_fn dflags0
 
   -- Figure out if the source has changed, for recompilation avoidance.
   --
-  -- Setting source_unchanged to True means that M.o seems
+  -- Setting source_unchanged to True means that M.o (or M.hie) seems
   -- to be up to date wrt M.hs; so no need to recompile unless imports have
   -- changed (which the compiler itself figures out).
   -- Setting source_unchanged to False tells the compiler that M.o is out of
@@ -1037,13 +1040,14 @@ runPhase (RealPhase (Hsc src_flavour)) input_fn dflags0
                 --      (b) we aren't going all the way to .o file (e.g. ghc -S)
              then return SourceModified
                 -- Otherwise look at file modification dates
-             else do dest_file_exists <- doesFileExist dest_file
-                     if not dest_file_exists
-                        then return SourceModified       -- Need to recompile
-                        else do t2 <- getModificationUTCTime dest_file
-                                if t2 > src_timestamp
-                                  then return SourceUnmodified
-                                  else return SourceModified
+             else do dest_file_mod <- sourceModified dest_file src_timestamp
+                     hie_file_mod <- if gopt Opt_WriteHie dflags
+                                        then sourceModified hie_file
+                                                            src_timestamp
+                                        else pure False
+                     if dest_file_mod || hie_file_mod
+                        then return SourceModified
+                        else return SourceUnmodified
 
         PipeState{hsc_env=hsc_env'} <- getPipeState
 
@@ -1062,6 +1066,7 @@ runPhase (RealPhase (Hsc src_flavour)) input_fn dflags0
                                         ms_obj_date  = Nothing,
                                         ms_parsed_mod   = Nothing,
                                         ms_iface_date   = Nothing,
+                                        ms_hie_date     = Nothing,
                                         ms_textual_imps = imps,
                                         ms_srcimps      = src_imps }
 
@@ -1634,8 +1639,9 @@ getLocation src_flavour mod_name = do
         location1 <- liftIO $ mkHomeModLocation2 dflags mod_name basename suff
 
         -- Boot-ify it if necessary
-        let location2 | HsBootFile <- src_flavour = addBootSuffixLocn location1
-                      | otherwise                 = location1
+        let location2
+              | HsBootFile <- src_flavour = addBootSuffixLocnOut location1
+              | otherwise                 = location1
 
 
         -- Take -ohi into account if present
@@ -2251,6 +2257,18 @@ writeInterfaceOnlyMode dflags =
  gopt Opt_WriteInterface dflags &&
  HscNothing == hscTarget dflags
 
+-- | Figure out if a source file was modified after an output file (or if we
+-- anyways need to consider the source file modified since the output is gone).
+sourceModified :: FilePath -- ^ destination file we are looking for
+               -> UTCTime  -- ^ last time of modification of source file
+               -> IO Bool  -- ^ do we need to regenerate the output?
+sourceModified dest_file src_timestamp = do
+  dest_file_exists <- doesFileExist dest_file
+  if not dest_file_exists
+    then return True       -- Need to recompile
+     else do t2 <- getModificationUTCTime dest_file
+             return (t2 <= src_timestamp)
+
 -- | What phase to run after one of the backend code generators has run
 hscPostBackendPhase :: DynFlags -> HscSource -> HscTarget -> Phase
 hscPostBackendPhase _ HsBootFile _    =  StopLn
diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs
index 9e93e47eeb..6c4ee86084 100644
--- a/compiler/main/DynFlags.hs
+++ b/compiler/main/DynFlags.hs
@@ -511,6 +511,7 @@ data GeneralFlag
    | Opt_OmitInterfacePragmas
    | Opt_ExposeAllUnfoldings
    | Opt_WriteInterface -- forces .hi files to be written even with -fno-code
+   | Opt_WriteHie -- generate .hie files
 
    -- profiling opts
    | Opt_AutoSccsOnIndividualCafs
@@ -544,6 +545,7 @@ data GeneralFlag
    | Opt_GhciSandbox
    | Opt_GhciHistory
    | Opt_GhciLeakCheck
+   | Opt_ValidateHie
    | Opt_LocalGhciHistory
    | Opt_NoIt
    | Opt_HelpfulErrors
@@ -942,12 +944,14 @@ data DynFlags = DynFlags {
   objectDir             :: Maybe String,
   dylibInstallName      :: Maybe String,
   hiDir                 :: Maybe String,
+  hieDir                :: Maybe String,
   stubDir               :: Maybe String,
   dumpDir               :: Maybe String,
 
   objectSuf             :: String,
   hcSuf                 :: String,
   hiSuf                 :: String,
+  hieSuf                :: String,
 
   canGenerateDynamicToo :: IORef Bool,
   dynObjectSuf          :: String,
@@ -1910,12 +1914,14 @@ defaultDynFlags mySettings (myLlvmTargets, myLlvmPasses) =
         objectDir               = Nothing,
         dylibInstallName        = Nothing,
         hiDir                   = Nothing,
+        hieDir                  = Nothing,
         stubDir                 = Nothing,
         dumpDir                 = Nothing,
 
         objectSuf               = phaseInputExt StopLn,
         hcSuf                   = phaseInputExt HCc,
         hiSuf                   = "hi",
+        hieSuf                  = "hie",
 
         canGenerateDynamicToo   = panic "defaultDynFlags: No canGenerateDynamicToo",
         dynObjectSuf            = "dyn_" ++ phaseInputExt StopLn,
@@ -2493,10 +2499,10 @@ getVerbFlags dflags
   | verbosity dflags >= 4 = ["-v"]
   | otherwise             = []
 
-setObjectDir, setHiDir, setStubDir, setDumpDir, setOutputDir,
+setObjectDir, setHiDir, setHieDir, setStubDir, setDumpDir, setOutputDir,
          setDynObjectSuf, setDynHiSuf,
          setDylibInstallName,
-         setObjectSuf, setHiSuf, setHcSuf, parseDynLibLoaderMode,
+         setObjectSuf, setHiSuf, setHieSuf, setHcSuf, parseDynLibLoaderMode,
          setPgmP, addOptl, addOptc, addOptP,
          addCmdlineFramework, addHaddockOpts, addGhciScript,
          setInteractivePrint
@@ -2506,18 +2512,24 @@ setOutputFile, setDynOutputFile, setOutputHi, setDumpPrefixForce
 
 setObjectDir  f d = d { objectDir  = Just f}
 setHiDir      f d = d { hiDir      = Just f}
+setHieDir     f d = d { hieDir     = Just f}
 setStubDir    f d = d { stubDir    = Just f
                       , includePaths = addGlobalInclude (includePaths d) [f] }
   -- -stubdir D adds an implicit -I D, so that gcc can find the _stub.h file
   -- \#included from the .hc file when compiling via C (i.e. unregisterised
   -- builds).
 setDumpDir    f d = d { dumpDir    = Just f}
-setOutputDir  f = setObjectDir f . setHiDir f . setStubDir f . setDumpDir f
+setOutputDir  f = setObjectDir f
+                . setHieDir f
+                . setHiDir f
+                . setStubDir f
+                . setDumpDir f
 setDylibInstallName  f d = d { dylibInstallName = Just f}
 
 setObjectSuf    f d = d { objectSuf    = f}
 setDynObjectSuf f d = d { dynObjectSuf = f}
 setHiSuf        f d = d { hiSuf        = f}
+setHieSuf       f d = d { hieSuf       = f}
 setDynHiSuf     f d = d { dynHiSuf     = f}
 setHcSuf        f d = d { hcSuf        = f}
 
@@ -3062,8 +3074,10 @@ dynamic_flags_deps = [
   , make_ord_flag defGhcFlag "dynosuf"           (hasArg setDynObjectSuf)
   , make_ord_flag defGhcFlag "hcsuf"             (hasArg setHcSuf)
   , make_ord_flag defGhcFlag "hisuf"             (hasArg setHiSuf)
+  , make_ord_flag defGhcFlag "hiesuf"            (hasArg setHieSuf)
   , make_ord_flag defGhcFlag "dynhisuf"          (hasArg setDynHiSuf)
   , make_ord_flag defGhcFlag "hidir"             (hasArg setHiDir)
+  , make_ord_flag defGhcFlag "hiedir"            (hasArg setHieDir)
   , make_ord_flag defGhcFlag "tmpdir"            (hasArg setTmpDir)
   , make_ord_flag defGhcFlag "stubdir"           (hasArg setStubDir)
   , make_ord_flag defGhcFlag "dumpdir"           (hasArg setDumpDir)
@@ -4088,6 +4102,7 @@ fFlagsDeps = [
   flagSpec "gen-manifest"                     Opt_GenManifest,
   flagSpec "ghci-history"                     Opt_GhciHistory,
   flagSpec "ghci-leak-check"                  Opt_GhciLeakCheck,
+  flagSpec "validate-ide-info"                Opt_ValidateHie,
   flagGhciSpec "local-ghci-history"           Opt_LocalGhciHistory,
   flagGhciSpec "no-it"                        Opt_NoIt,
   flagSpec "ghci-sandbox"                     Opt_GhciSandbox,
@@ -4143,6 +4158,7 @@ fFlagsDeps = [
   flagSpec "strictness"                       Opt_Strictness,
   flagSpec "use-rpaths"                       Opt_RPath,
   flagSpec "write-interface"                  Opt_WriteInterface,
+  flagSpec "write-ide-info"                   Opt_WriteHie,
   flagSpec "unbox-small-strict-fields"        Opt_UnboxSmallStrictFields,
   flagSpec "unbox-strict-fields"              Opt_UnboxStrictFields,
   flagSpec "version-macros"                   Opt_VersionMacros,
diff --git a/compiler/main/Finder.hs b/compiler/main/Finder.hs
index 57d608bbf7..2db0a5e0b4 100644
--- a/compiler/main/Finder.hs
+++ b/compiler/main/Finder.hs
@@ -482,23 +482,27 @@ mkHomeModLocation2 dflags mod src_basename ext = do
 
        obj_fn = mkObjPath  dflags src_basename mod_basename
        hi_fn  = mkHiPath   dflags src_basename mod_basename
+       hie_fn = mkHiePath  dflags src_basename mod_basename
 
    return (ModLocation{ ml_hs_file   = Just (src_basename <.> ext),
                         ml_hi_file   = hi_fn,
-                        ml_obj_file  = obj_fn })
+                        ml_obj_file  = obj_fn,
+                        ml_hie_file  = hie_fn })
 
 mkHiOnlyModLocation :: DynFlags -> Suffix -> FilePath -> String
                     -> IO ModLocation
 mkHiOnlyModLocation dflags hisuf path basename
  = do let full_basename = path </> basename
           obj_fn = mkObjPath  dflags full_basename basename
+          hie_fn = mkHiePath  dflags full_basename basename
       return ModLocation{    ml_hs_file   = Nothing,
                              ml_hi_file   = full_basename <.> hisuf,
                                 -- Remove the .hi-boot suffix from
                                 -- hi_file, if it had one.  We always
                                 -- want the name of the real .hi file
                                 -- in the ml_hi_file field.
-                             ml_obj_file  = obj_fn
+                             ml_obj_file  = obj_fn,
+                             ml_hie_file  = hie_fn
                   }
 
 -- | Constructs the filename of a .o file for a given source file.
@@ -532,6 +536,21 @@ mkHiPath dflags basename mod_basename = hi_basename <.> hisuf
                 hi_basename | Just dir <- hidir = dir </> mod_basename
                             | otherwise         = basename
 
+-- | Constructs the filename of a .hie file for a given source file.
+-- Does /not/ check whether the .hie file exists
+mkHiePath
+  :: DynFlags
+  -> FilePath           -- the filename of the source file, minus the extension
+  -> String             -- the module name with dots replaced by slashes
+  -> FilePath
+mkHiePath dflags basename mod_basename = hie_basename <.> hiesuf
+ where
+                hiedir = hieDir dflags
+                hiesuf = hieSuf dflags
+
+                hie_basename | Just dir <- hiedir = dir </> mod_basename
+                             | otherwise          = basename
+
 
 
 -- -----------------------------------------------------------------------------
diff --git a/compiler/main/GhcMake.hs b/compiler/main/GhcMake.hs
index 39b6427173..8b2bc01ffe 100644
--- a/compiler/main/GhcMake.hs
+++ b/compiler/main/GhcMake.hs
@@ -2186,6 +2186,8 @@ summariseFile hsc_env old_summaries file mb_phase obj_allowed maybe_buf
                         then liftIO $ getObjTimestamp location NotBoot
                         else return Nothing
                   hi_timestamp <- maybeGetIfaceDate dflags location
+                  let hie_location = ml_hie_file location
+                  hie_timestamp <- modificationTimeIfExists hie_location
 
                   -- We have to repopulate the Finder's cache because it
                   -- was flushed before the downsweep.
@@ -2193,7 +2195,8 @@ summariseFile hsc_env old_summaries file mb_phase obj_allowed maybe_buf
                     (moduleName (ms_mod old_summary)) (ms_location old_summary)
 
                   return old_summary{ ms_obj_date = obj_timestamp
-                                    , ms_iface_date = hi_timestamp }
+                                    , ms_iface_date = hi_timestamp
+                                    , ms_hie_date = hie_timestamp }
            else
                 new_summary src_timestamp
 
@@ -2232,6 +2235,7 @@ summariseFile hsc_env old_summaries file mb_phase obj_allowed maybe_buf
                 else return Nothing
 
         hi_timestamp <- maybeGetIfaceDate dflags location
+        hie_timestamp <- modificationTimeIfExists (ml_hie_file location)
 
         extra_sig_imports <- findExtraSigImports hsc_env hsc_src mod_name
         required_by_imports <- implicitRequirements hsc_env the_imps
@@ -2247,6 +2251,7 @@ summariseFile hsc_env old_summaries file mb_phase obj_allowed maybe_buf
                              ms_textual_imps = the_imps ++ extra_sig_imports ++ required_by_imports,
                              ms_hs_date = src_timestamp,
                              ms_iface_date = hi_timestamp,
+                             ms_hie_date = hie_timestamp,
                              ms_obj_date = obj_timestamp })
 
 findSummaryBySourceFile :: [ModSummary] -> FilePath -> Maybe ModSummary
@@ -2304,8 +2309,10 @@ summariseModule hsc_env old_summary_map is_boot (L loc wanted_mod)
                        then getObjTimestamp location is_boot
                        else return Nothing
                 hi_timestamp <- maybeGetIfaceDate dflags location
+                hie_timestamp <- modificationTimeIfExists (ml_hie_file location)
                 return (Just (Right old_summary{ ms_obj_date = obj_timestamp
-                                               , ms_iface_date = hi_timestamp}))
+                                               , ms_iface_date = hi_timestamp
+                                               , ms_hie_date = hie_timestamp }))
         | otherwise =
                 -- source changed: re-summarise.
                 new_summary location (ms_mod old_summary) src_fn src_timestamp
@@ -2389,6 +2396,7 @@ summariseModule hsc_env old_summary_map is_boot (L loc wanted_mod)
               else return Nothing
 
         hi_timestamp <- maybeGetIfaceDate dflags location
+        hie_timestamp <- modificationTimeIfExists (ml_hie_file location)
 
         extra_sig_imports <- findExtraSigImports hsc_env hsc_src mod_name
         required_by_imports <- implicitRequirements hsc_env the_imps
@@ -2404,6 +2412,7 @@ summariseModule hsc_env old_summary_map is_boot (L loc wanted_mod)
                               ms_textual_imps = the_imps ++ extra_sig_imports ++ required_by_imports,
                               ms_hs_date   = src_timestamp,
                               ms_iface_date = hi_timestamp,
+                              ms_hie_date = hie_timestamp,
                               ms_obj_date  = obj_timestamp })))
 
 
diff --git a/compiler/main/HscMain.hs b/compiler/main/HscMain.hs
index 9b9edf7d21..c2c912451b 100644
--- a/compiler/main/HscMain.hs
+++ b/compiler/main/HscMain.hs
@@ -85,6 +85,7 @@ module HscMain
 import GhcPrelude
 
 import Data.Data hiding (Fixity, TyCon)
+import Data.Maybe       ( fromJust )
 import Id
 import GHCi             ( addSptEntry )
 import GHCi.RemoteTypes ( ForeignHValue )
@@ -167,10 +168,15 @@ import Data.IORef
 import System.FilePath as FilePath
 import System.Directory
 import System.IO (fixIO)
-import qualified Data.Map as Map
+import qualified Data.Map as M
 import qualified Data.Set as S
 import Data.Set (Set)
 
+import HieAst           ( mkHieFile )
+import HieTypes         ( getAsts, hie_asts )
+import HieBin           ( readHieFile, writeHieFile )
+import HieDebug         ( diffFile, validateScopes )
+
 #include "HsVersions.h"
 
 
@@ -379,8 +385,8 @@ hscParse' mod_summary
                       hpm_module    = rdr_module,
                       hpm_src_files = srcs2,
                       hpm_annotations
-                              = (Map.fromListWith (++) $ annotations pst,
-                                 Map.fromList $ ((noSrcSpan,comment_q pst)
+                              = (M.fromListWith (++) $ annotations pst,
+                                 M.fromList $ ((noSrcSpan,comment_q pst)
                                                  :(annotations_comments pst)))
                    }
 
@@ -392,15 +398,41 @@ hscParse' mod_summary
 
 -- -----------------------------------------------------------------------------
 -- | If the renamed source has been kept, extract it. Dump it if requested.
-extract_renamed_stuff :: TcGblEnv -> Hsc (TcGblEnv, RenamedStuff)
-extract_renamed_stuff tc_result = do
+extract_renamed_stuff :: ModSummary -> TcGblEnv -> Hsc RenamedStuff
+extract_renamed_stuff mod_summary tc_result = do
     let rn_info = getRenamedStuff tc_result
 
     dflags <- getDynFlags
     liftIO $ dumpIfSet_dyn dflags Opt_D_dump_rn_ast "Renamer" $
                            showAstData NoBlankSrcSpan rn_info
 
-    return (tc_result, rn_info)
+    -- Create HIE files
+    when (gopt Opt_WriteHie dflags) $ do
+        hieFile <- mkHieFile mod_summary (tcg_binds tc_result)
+                                         (fromJust rn_info)
+        let out_file = ml_hie_file $ ms_location mod_summary
+        liftIO $ writeHieFile out_file hieFile
+
+        -- Validate HIE files
+        when (gopt Opt_ValidateHie dflags) $ do
+            hs_env <- Hsc $ \e w -> return (e, w)
+            liftIO $ do
+              -- Validate Scopes
+              case validateScopes $ getAsts $ hie_asts hieFile of
+                  [] -> putMsg dflags $ text "Got valid scopes"
+                  xs -> do
+                    putMsg dflags $ text "Got invalid scopes"
+                    mapM_ (putMsg dflags) xs
+              -- Roundtrip testing
+              nc <- readIORef $ hsc_NC hs_env
+              (file', _) <- readHieFile nc out_file
+              case diffFile hieFile file' of
+                [] ->
+                  putMsg dflags $ text "Got no roundtrip errors"
+                xs -> do
+                  putMsg dflags $ text "Got roundtrip errors"
+                  mapM_ (putMsg dflags) xs
+    return rn_info
 
 
 -- -----------------------------------------------------------------------------
@@ -408,22 +440,23 @@ extract_renamed_stuff tc_result = do
 hscTypecheckRename :: HscEnv -> ModSummary -> HsParsedModule
                    -> IO (TcGblEnv, RenamedStuff)
 hscTypecheckRename hsc_env mod_summary rdr_module = runHsc hsc_env $ do
-      tc_result <- hscTypecheck True mod_summary (Just rdr_module)
-      extract_renamed_stuff tc_result
+    tc_result <- hsc_typecheck True mod_summary (Just rdr_module)
+    rn_info <- extract_renamed_stuff mod_summary tc_result
+    return (tc_result, rn_info)
 
+-- | Rename and typecheck a module, but don't return the renamed syntax
 hscTypecheck :: Bool -- ^ Keep renamed source?
              -> ModSummary -> Maybe HsParsedModule
              -> Hsc TcGblEnv
 hscTypecheck keep_rn mod_summary mb_rdr_module = do
-    tc_result <- hscTypecheck' keep_rn mod_summary mb_rdr_module
-    _ <- extract_renamed_stuff tc_result
+    tc_result <- hsc_typecheck keep_rn mod_summary mb_rdr_module
+    _ <- extract_renamed_stuff mod_summary tc_result
     return tc_result
 
-
-hscTypecheck' :: Bool -- ^ Keep renamed source?
+hsc_typecheck :: Bool -- ^ Keep renamed source?
               -> ModSummary -> Maybe HsParsedModule
               -> Hsc TcGblEnv
-hscTypecheck' keep_rn mod_summary mb_rdr_module = do
+hsc_typecheck keep_rn mod_summary mb_rdr_module = do
     hsc_env <- getHscEnv
     let hsc_src = ms_hsc_src mod_summary
         dflags = hsc_dflags hsc_env
@@ -433,6 +466,7 @@ hscTypecheck' keep_rn mod_summary mb_rdr_module = do
         inner_mod = canonicalizeHomeModule dflags mod_name
         src_filename  = ms_hspp_file mod_summary
         real_loc = realSrcLocSpan $ mkRealSrcLoc (mkFastString src_filename) 1 1
+        keep_rn' = gopt Opt_WriteHie dflags || keep_rn
     MASSERT( moduleUnitId outer_mod == thisPackage dflags )
     if hsc_src == HsigFile && not (isHoleModule inner_mod)
         then ioMsgMaybe $ tcRnInstantiateSignature hsc_env outer_mod' real_loc
@@ -440,7 +474,7 @@ hscTypecheck' keep_rn mod_summary mb_rdr_module = do
          do hpm <- case mb_rdr_module of
                     Just hpm -> return hpm
                     Nothing -> hscParse' mod_summary
-            tc_result0 <- tcRnModule' mod_summary keep_rn hpm
+            tc_result0 <- tcRnModule' mod_summary keep_rn' hpm
             if hsc_src == HsigFile
                 then do (iface, _, _) <- liftIO $ hscSimpleIface hsc_env tc_result0 Nothing
                         ioMsgMaybe $
@@ -1411,7 +1445,8 @@ hscCompileCmmFile hsc_env filename output_filename = runHsc hsc_env $ do
   where
     no_loc = ModLocation{ ml_hs_file  = Just filename,
                           ml_hi_file  = panic "hscCompileCmmFile: no hi file",
-                          ml_obj_file = panic "hscCompileCmmFile: no obj file" }
+                          ml_obj_file = panic "hscCompileCmmFile: no obj file",
+                          ml_hie_file = panic "hscCompileCmmFile: no hie file"}
 
 -------------------- Stuff for new code gen ---------------------
 
@@ -1591,7 +1626,8 @@ hscDeclsWithLocation hsc_env0 str source linenumber =
     -- We use a basically null location for iNTERACTIVE
     let iNTERACTIVELoc = ModLocation{ ml_hs_file   = Nothing,
                                       ml_hi_file   = panic "hsDeclsWithLocation:ml_hi_file",
-                                      ml_obj_file  = panic "hsDeclsWithLocation:ml_hi_file"}
+                                      ml_obj_file  = panic "hsDeclsWithLocation:ml_obj_file",
+                                      ml_hie_file  = panic "hsDeclsWithLocation:ml_hie_file" }
     ds_result <- hscDesugar' iNTERACTIVELoc tc_gblenv
 
     {- Simplify -}
diff --git a/compiler/main/HscTypes.hs b/compiler/main/HscTypes.hs
index d0cf7e0dd8..456332daeb 100644
--- a/compiler/main/HscTypes.hs
+++ b/compiler/main/HscTypes.hs
@@ -2752,6 +2752,8 @@ data ModSummary
           -- ^ Timestamp of hi file, if we *only* are typechecking (it is
           -- 'Nothing' otherwise.
           -- See Note [Recompilation checking in -fno-code mode] and #9243
+        ms_hie_date   :: Maybe UTCTime,
+          -- ^ Timestamp of hie file, if we have one
         ms_srcimps      :: [(Maybe FastString, Located ModuleName)],
           -- ^ Source imports of the module
         ms_textual_imps :: [(Maybe FastString, Located ModuleName)],
@@ -2833,7 +2835,7 @@ showModMsg dflags target recomp mod_summary = showSDoc dflags $
 {-
 ************************************************************************
 *                                                                      *
-\subsection{Recmpilation}
+\subsection{Recompilation}
 *                                                                      *
 ************************************************************************
 -}